<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>三行两列布局</title>
    <style>
        html, body {
            margin: 0;
        }

        #container {
            height: 500px;
            width: 100%;
            background-color: #b5eea2;
        }

        .nav {
            border:1px red solid;
            position: relative;
            float: left;
            width: 49%;
            height: 480px;
            text-align: center;
        }

        .nav img {
            position: absolute;
            margin-top: 150px;
            margin-left:-100px;
            width: 200px;
            height: 200px;
        }
    </style>
</head>
<body>
<div id="container">
    <div class="nav">
        <img src="http://climg.mukewang.com/58c0f808000129a303600215.jpg"
             alt="Test">
    </div>
    <div class="nav">
        <img src="http://climg.mukewang.com/58c0f819000198a703600214.jpg"
             alt="Test">
    </div>
</div>
</body>
</html>